And arguably even more important: you should be able to read all these plots. This isn't ~secret advanced stuff~ it's what I'd expect a junior ML engineer to know in a job interview.
Anyway, if you're looking for a good very intro guide, I like:
The R for Data Science chapter for R: https://r4ds.had.co.nz/data-visualisation.html
The @swcarpentry@twitter.com intro to Python: https://swcarpentry.github.io/python-novice-inflammation/
(Notice that plotting is basically the first thing taught in these courses! Not a coincidence!)
Look through literally any system-based ML paper. They've all got figures! Because they're necessary! And many, many, many more were likely created during the research and development process.